Resonator delete
 

Hey y’all l, I own an 03 s2000 with stock exhaust, but have had straight through mufflers instead of stock, I was thinking of getting rid of the resonator, but was wondering how it would effect the sound? Thanks.

Probably make it louder.

Drone?
 

Would it be louder at all rpms or mainly at low rpms? Currently it is pretty droney but not that loud at high rpms.

The resonator prevents your exhaust from hitting a resonant frequency in its operating range. If you remove the resonator your exhaust will get very loud at or near a specific rpm. I don't know what that rpm is, but you'll find out very quickly if you remove the resonator. It's not just loud, it resonates throughout the car making it unbearable.

Its a helmoltz resonator. It doesn't impede flow. As stated, it reduces drone at specific rpms. Deleting it would not make it louder, just more drone.

Loud
 

Would a test pipe be a better option to make it louder, but not increase drone?

Yes, environmentally irresponsible as it may be...

Test pipe
 

How much louder would a test pipe make it?

Diameter
 

Given that I am on a stock exhaust diameter, which test pipe would be the best pipe for my exhaust?

Not a lot louder, but noticeable.

Match exhaust diameter. 63.5mm tp.